Have IAX2 optimize the codec translation path just like chan_sip does it. If

the caller's codec is in our codec list, move it to the top to avoid transcoding.

(closes issue #10500)
Reported by: stevedavies
Patches:
      iax-prefer-current-codec.patch uploaded by stevedavies (license 184)
      iax-prefer-current-codec.1.4.patch uploaded by stevedavies (license 184)
Tested by: stevedavies, pj, sheldonh


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@99004 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_iax2.c

@@ -2896,12 +2896,13 @@ struct create_addr_info {
 	char mohsuggest[MAX_MUSICCLASS];
 };
 
-static int create_addr(const char *peername, struct sockaddr_in *sin, struct create_addr_info *cai)
+static int create_addr(const char *peername, struct ast_channel *c, struct sockaddr_in *sin, struct create_addr_info *cai)
 {
 	struct ast_hostent ahp;
 	struct hostent *hp;
 	struct iax2_peer *peer;
 	int res = -1;
+	struct ast_codec_pref ourprefs;
 
 	ast_clear_flag(cai, IAX_SENDANI | IAX_TRUNK);
 	cai->sockfd = defaultsockfd;
@@ -2916,7 +2917,11 @@ static int create_addr(const char *peername, struct sockaddr_in *sin, struct cre
 			memcpy(&sin->sin_addr, hp->h_addr, sizeof(sin->sin_addr));
 			sin->sin_port = htons(IAX_DEFAULT_PORTNO);
 			/* use global iax prefs for unknown peer/user */
-			ast_codec_pref_convert(&prefs, cai->prefs, sizeof(cai->prefs), 1);
+			/* But move the calling channel's native codec to the top of the preference list */
+			memcpy(&ourprefs, &prefs, sizeof(ourprefs));
+			if (c)
+				ast_codec_pref_prepend(&ourprefs, c->nativeformats, 1);
+			ast_codec_pref_convert(&ourprefs, cai->prefs, sizeof(cai->prefs), 1);
 			return 0;
 		} else {
 			ast_log(LOG_WARNING, "No such host: %s\n", peername);
@@ -2940,7 +2945,13 @@ static int create_addr(const char *peername, struct sockaddr_in *sin, struct cre
 	cai->encmethods = peer->encmethods;
 	cai->sockfd = peer->sockfd;
 	cai->adsi = peer->adsi;
-	ast_codec_pref_convert(&peer->prefs, cai->prefs, sizeof(cai->prefs), 1);
+	memcpy(&ourprefs, &peer->prefs, sizeof(ourprefs));
+	/* Move the calling channel's native codec to the top of the preference list */
+	if (c) {
+		ast_log(LOG_DEBUG, "prepending %x to prefs\n", c->nativeformats);
+		ast_codec_pref_prepend(&ourprefs, c->nativeformats, 1);
+	}
+	ast_codec_pref_convert(&ourprefs, cai->prefs, sizeof(cai->prefs), 1);
 	ast_copy_string(cai->context, peer->context, sizeof(cai->context));
 	ast_copy_string(cai->peercontext, peer->peercontext, sizeof(cai->peercontext));
 	ast_copy_string(cai->username, peer->username, sizeof(cai->username));
@@ -3115,7 +3126,7 @@ static int iax2_call(struct ast_channel *c, char *dest, int timeout)
 	if (!pds.exten)
 		pds.exten = defaultrdest;
 
-	if (create_addr(pds.peer, &sin, &cai)) {
+	if (create_addr(pds.peer, c, &sin, &cai)) {
 		ast_log(LOG_WARNING, "No address associated with '%s'\n", pds.peer);
 		return -1;
 	}
@@ -8499,7 +8510,7 @@ static int iax2_provision(struct sockaddr_in *end, int sockfd, char *dest, const
 	if (end) {
 		memcpy(&sin, end, sizeof(sin));
 		cai.sockfd = sockfd;
-	} else if (create_addr(dest, &sin, &cai))
+	} else if (create_addr(dest, NULL, &sin, &cai))
 		return -1;
 
 	/* Build the rest of the message */
@@ -8722,7 +8733,7 @@ static struct ast_channel *iax2_request(const char *type, int format, void *data
 	       
 	
 	/* Populate our address from the given */
-	if (create_addr(pds.peer, &sin, &cai)) {
+	if (create_addr(pds.peer, NULL, &sin, &cai)) {
 		*cause = AST_CAUSE_UNREGISTERED;
 		return NULL;
 	}
@@ -10037,7 +10048,7 @@ static int cache_get_callno_locked(const char *data)
 	parse_dial_string(tmpstr, &pds);
 
 	/* Populate our address from the given */
-	if (create_addr(pds.peer, &sin, &cai))
+	if (create_addr(pds.peer, NULL, &sin, &cai))
 		return -1;
 
 	if (option_debug)

include/asterisk/frame.h

@@ -505,6 +505,10 @@ void ast_codec_pref_remove(struct ast_codec_pref *pref, int format);
 */
 int ast_codec_pref_append(struct ast_codec_pref *pref, int format);
 
+/*! \brief Prepend an audio codec to a preference list, removing it first if it was already there 
+*/
+void ast_codec_pref_prepend(struct ast_codec_pref *pref, int format, int only_if_existing);
+
 /*! \brief Select the best audio format according to preference list from supplied options. 
    If "find_best" is non-zero then if nothing is found, the "Best" format of 
    the format list is selected, otherwise 0 is returned. */

main/frame.c

@@ -1149,7 +1149,7 @@ void ast_codec_pref_remove(struct ast_codec_pref *pref, int format)
 /*! \brief Append codec to list */
 int ast_codec_pref_append(struct ast_codec_pref *pref, int format)
 {
-	int x, newindex = -1;
+	int x, newindex = 0;
 
 	ast_codec_pref_remove(pref, format);
 
@@ -1172,6 +1172,42 @@ int ast_codec_pref_append(struct ast_codec_pref *pref, int format)
 	return x;
 }
 
+/*! \brief Prepend codec to list */
+void ast_codec_pref_prepend(struct ast_codec_pref *pref, int format, int only_if_existing)
+{
+	int x, newindex = 0;
+
+	/* First step is to get the codecs "index number" */
+	for (x = 0; x < ARRAY_LEN(AST_FORMAT_LIST); x++) {
+		if (AST_FORMAT_LIST[x].bits == format) {
+			newindex = x + 1;
+			break;
+		}
+	}
+	/* Done if its unknown */
+	if (!newindex)
+		return;
+
+	/* Now find any existing occurrence, or the end */
+	for (x = 0; x < 32; x++) {
+		if (!pref->order[x] || pref->order[x] == newindex)
+			break;
+	}
+
+	if (only_if_existing && !pref->order[x])
+		return;
+
+	/* Move down to make space to insert - either all the way to the end,
+	   or as far as the existing location (which will be overwritten) */
+	for (; x > 0; x--) {
+		pref->order[x] = pref->order[x - 1];
+		pref->framing[x] = pref->framing[x - 1];
+	}
+
+	/* And insert the new entry */
+	pref->order[0] = newindex;
+	pref->framing[0] = 0; /* ? */
+}
 
 /*! \brief Set packet size for codec */
 int ast_codec_pref_setsize(struct ast_codec_pref *pref, int format, int framems)